As Floyd Mayweather drove home from work in early May he was thinking about retirement, thinking about a final fight and then a peaceful life away from the ring.

He cleared $250m (£162m) that night at the MGM in Las Vegas when his fists slowly tamed Manny Pacquiao in boxing's most eagerly anticipated, richest and ultimately disappointing fight.

Back at the MGM, which has hosted Mayweather's last 11 fights, the boxer will step through the ropes to meet Andre Berto in what will be, so he insists, his 49th and last fight. He claims that he will equal Rocky Marciano's record of 49 wins, no losses, and then retire as world champion. However, nobody believes him

Marciano was just 32 years and 20 days old when he fought for the last time and walked away from the sport after six defences of the world heavyweight title during a three-year reign. The Rock's raw statistics have long since been eclipsed by Mayweather, who is 38 and has won 25 world title fights during 17 years as champion.

"I know why Floyd selected me," said Berto. "Has he never heard of boxing's great upsets, fights when the underdog won? I'm that man. I have won two world titles, I'm deserving - I'm ready, he's in for a shock."

Assuming Berto stands and fights there is every chance Mayweather will get his first legitimate stoppage since that dreadful night of tears eight years ago when Ricky Hatton was knocked out in 10 rounds. Mayweather walked away after that fight, claiming he wanted to diversify, but the neon lured him back.

Even now he has a lot of interests outside boxing to distract him and add to Berto's theory that he has taken him lightly. There is the make-up business, the music production and the shoe industry that he aims to dominate. There is also the boxing management company and on the undercard his WBC super-middleweight champion, Badou Jack, fights George Groves.

Meanwhile, at the O2 Arena in London, Anthony Joshua will move closer to his first million if he can defeat unbeaten Gary Cornish for the Commonwealth heavyweight title.